1. Field of the Invention
The present invention relates generally to equipment for the dispensing of viscous materials, and more specifically to equipment for dispensing condiments.
2. Background
Various types of pumps are known for use in pumping viscous substances, such as diaphragm pumps and fixed and rotary peristaltic pumps. Condiments, such as ketchup and mustard, are well known examples of viscous products that are dispensed using such pumps as the driving force therefor. Automated dispensing systems for condiments are useful to save time in high volume applications such as are found "behind the counter" in fast food restaurants. These systems are also useful in self serve applications in place of, for example, individual packets and manual pump systems. The condiment packets can represent an environmental and cleanliness concern, and the manual pump systems may be activated too forcefully by an individual thereby resulting in waste and mess. Thus, a motorized pump system can provide the advantage of always delivering the condiment at a known predetermined flow rate thereby resulting in a more predictable, less wasteful and more cleanly condiment dispensing station. As such systems typically pump the condiments from bag-in-box containers, the overall approach is less susceptible to contamination and the frequency of refilling is less than in other dispensing approaches.
However, a problem with motorized condiment dispensing systems concerns the tendency for small amounts of condiment to drip from the delivery spout or point after dispensing thereof. Such dripping represents waste, and over time accumulates at the dispensing station requiring cleaning thereof. One approach to this problem has been to stop dispensing by stopping the pump and simultaneously fully occluding a flexible portion of hose through which the condiment is pumped to the dispense point However, condiment continues to remain at the dispense point and can nevertheless drip therefrom. A further approach has been to run the pump in the reverse direction after each dispensing, thereby sucking the condiment back away from the dispense point. However, this approach may not be possible depending on the type of pump employed, and in any event, requires that the pump be run an additional amount causing further wear thereon.
Accordingly, it would be desirable to have a means in conjunction with a motorized dispensing approach for viscous materials, such as condiments, that alleviates the problem of post dispensing dripping but that does not require the full occlusion of a tube or the further running of a pump.